Electroplating anode



June 14,. 1960 J. R. DYSON 2,940,917

ELECTROPLATING ANODE I Filed Nov. 7, 1957 5 Sheets-Sheet l -:q I m IN V EN TOR. 2 JOHN e. DVSOA/ BY M June 14,. 1960 J. R. DYSON ELECTROPLATING ANODE' 3 Sheets-Sheet 2 Filed NOV. '7, 1957 IN V EN TOR. JOA/A/ e. oyso/v BY 6' nrrae/va s I J. R. DYSON ELECTROPLATING ANODE June 14, 196Q s Sheets-Sheet 3 Filed Nov. 7, 1957 INVENTOR. JOHN E. DVSOA/ 01;... x arr-02mg;

iitdted States Patent ELECI'RGPLATING AN ODE .iohn 1R. Dyson, Bell, Calif., assignor to Chrome Crankshaft (30., Incorporated, Los Angeles, Calif., a corporation of California Filed Nov. 7, 1957, Ser. No. 695,165

1 Claim. (Cl. 204-212) This invention relates to an improved anode structure for use in chromium plating crank pins and main journals of crankshafts as well as similar cylindrical surfaces.

In the reconditioning of large crankshafts such as utilized in railroad locomotives part of the reconditioning involves immersing and rotating the shaft in a chromic acid bath wherein the shaft serves as a cathode and an anode is spaced from the portion of the shaft to be plated causing a chromium deposit upon said shaft as same is rotated.

it is an object of this invention to provide an improved anode structure for use in said process.

it is a further object of this invention to provide an anode which is readily and easily positioned with respect to the crankshaft.

it is still a further object of this invention to provide a lighter more easily handled anode with a minimum of surface exposed to corrosion in the chromic acid bath.

Still a further object of this invention is to provide an anode having the above characteristics which will deposit a chromium layer of uniform thickness and of desired hardness, brightness and density upon the shaft being plated.

Other objects and advantages will be readily apparent from the following description.

In the drawings:

Figure 1 is a section of a chromium bath having an anode embodying this invention therein.

Figure 2 is a view taken along line 2-2 of Figure 1.

Figure 3 is a perspective view of the anode.

Figure 4 is a side elevation of the anode illustrating its mounting upon the crankshaft.

Figure 5 is a view taken along line 5-5 of Figure 3.

Figure 6 is a perspective view of the plastic shield.

Figure 7 is a fragmentary perspective of the anode.

Figure 8 is a. view taken along line 88 of Figure 3.

Figure 9 is a side elevation of a modified form of this invention.

Figure 10 is a. view taken along line 16-10 of Figure 9.

The crankshaft 16 is rotatably supported within a tank 12 while immersed in a chromic acid bath in a manner well known to those skilled in the art. A pair of longitudinal rods 14 and 16 are supported above the bath to' confine the arms of the anode as is well known in the art. This particular invention is concerned with the anode structure.

A pair of arms 18 and 20 each terminate in a block 22 and 24 respectively. Each block has a bore therethrough receiving pin 26 held in said blocks by set screws such as 28 which seat in a suitable peripheral groove such as 30 in said pin. Thus the arms 18 and 20 may be pivoted with respect to one another as stop 32 on one block limits pivoting when the arms are parallel.

Block 24 has secured thereto an open ended wire frame 34 which in this instance is welded thereto. The frame is arcuate and has secured thereon an arcuate plate or anode 36 which is formed of a suitable electrical conducting material which resists corrosion in the bath such as lead and has a series of perforations 38 therein permitting passage of gases therethrough. Block 22 has a similar frame 46 and anode 42 fixed thereto opposing anode 36. The inner faces of the anodes are arcuate and concentric to shaft 16 when in the closed or operative position of Fig "e 1. v

A ball bearing 44 is rotatably mounted in cage 46 which in turn is secured to frame 34. Four such ball bearings are provided one upon each arm of open frames 34 and .0 between blocks 22 and 24 and anodes 36 and 42.

Thus when the arms are pivoted from the open posi tion of Figure 4 to the closed position of Figure l the ball bearings rest upon shaft 10 and space the anodes 36 and 42 approximately one inch from the surface to be plated.

The shaft ll) being plated is connected to the negative while the anodes to the positive of a source of current inducing current flow which results in chromium deposit upon shaft 10.

The current is supplied to the anode by a wire 48 which is clamped to the inner electrical conductive core 50 of either arm 18 or 29 and to a suitable bus bar (not shown). Surrounding the core of each arm is a suitable electrically non-conductive coating 51 which extends to the block at the lower extremity of the arm. The block and frames 34 and 40 may be covered with a suitable non-conductive coating 55 which shield ball bearings as from the source of elecu'icity but terminate where the anodes 36 and 42 are mounted upon the frame. The coating 55 may take the form of a paint or tape which is corrosion resistant with respect to the chromic acid bath.

Thus as shaft 10 is rotated in the bath 12 the anodes 36 and 42 remain at a fixed distance with respect to the cylindrical surface of the shaft and yet free to move in the bath by virtue of balls 44 supporting the anode assembly on the shaft.

A pair of plastic shields such as 54 (see Fig. 6) may be positioned on shaft 10 on either side of the anode assembly to limit the area of plating between same (see Fig. 2).

In Figures 9 and 10 a modification is illustrated. In this embodiment the frames 34a and 40a are closed instead of open ended to provide increased rigidity and a plastic roller such as 56 is rotatably mounted in such frame between the anode and the block to form the support for the anode structure on shaft 10a.

While what hereinbefore has been described as the preferred embodiment of this invention, it is readily apparent that alterations and modifications can be resorted to Without departing from the scope of this invention and such alterations and modifications are intended to be included within the scope of the appended claim.

I claim:

An anode structure for chromium electroplating a portion of a cylindrical crankshaft as same .is being rotated comprising: a pair of pivotally connected arms, an anode plate attached to a corresponding end of each arm whereby pivoting of said arms moves said anode plates towards or away from one another, said anode plates having arcuate inner faces the curvature of which is concentric with said shaft and bearing means carried adjacent said anode plates engaging the shaft to be plated and supporting said anode structure upon said shaft with the inner faces of said anode plates radially disposed an Patented June 14, 1960-.

distance with respect-to said shaft, ma Bearing 2,471,808

Jones Q Aug. 2, 1949 Vrilakas June 14, 1955 FOREIGN PATENTS France 1 Sept. 1, 1942 France Apr. 14, 1947 Germany Sept. 27, 1951 V 

